Preventing Water Contamination In Diesel

Mar 14, 2018 1:26:39 PM

Are you managing your fuel quality?

I had an interesting discussion with a friend the other day about some recent injector failures. They’d suffered a couple of low hour failures and trying to determine the root cause. There can be many causes, but one came up that I am passionate about. That cause is water contamination in diesel.

In this case, it was unlikely a cause for injector failure, but it is a problem that we are often unaware of. It can cause serious issues in your mining fleet. It can, and has in the past, stopped an entire mine when not managed. When this situation of water in fuel is allowed to occur, it is not one that is easy to rectify.

In the case of water in fuel, prevention is so much better than the cure.

Let’s start with how water causes a problem. The biggest risk of water in fuel is the dreaded fuel bug. Without going technical, just know it lives in water and feeds on fuel. If the temperature of the fuel gets to 23 degrees Celsius, and there is water present, the fuel bug will breed. (If you don’t think your fuel can heat up like that, measure the temperature of the fuel return line) Breeding doesn’t happen slowly, but very quickly, (often described as blooming like flowers opening all at once) and will reduce the quality of the fuel at a very rapid rate. It will also quickly go through its life cycle of eating, breeding, excreting and dying. So, along with the fuel deterioration, you get a whole lot of slimy sludge which then blocks your filters and forms a lining on your fuel lines and tanks. Subsequently, trucks, diggers, and the boss’s Landcruiser stop running!

Now, what do you do? Some people use biocides or fuel treatments to try and kill the bug. This might work to kill the bug and improve the fuel enough so it can be burnt, but it won’t stop a new batch if the water remains. This approach won’t fix the sludge in the tank either, that has to be done manually. Basically, you have to replace the contaminated fuel with good fuel and clean any affected tanks.

Figure 1 Parker Velcon Vertical Filter/ Separator Coalescer Vessel

The impact can be catastrophic for a mine and the source can be difficult to find. There should not be many opportunities for water ingress within a sites fuel storage and distribution infrastructure. Most of the water you will find enters the storage tanks, either through poor shipping and transport practices or into the storage tanks from corrosion, damage, and even tank vents. It often happens over a long period of time where the water slowly builds up in the bottom of the tank.

It is not difficult to prevent this problem. The key points below will prevent water contamination in diesel where it enters through the storage systems.

  • - Ensure that there is a program to regularly check and drain water from your storage tanks, at least once a month.
  • - Install a high quality filter coalescer in the fuel line between the storage tanks and dispensing station.
  • - Establish a maintenance regime to manage the filter and make sure you have spare filter elements in stock.

Having a filter coalescer will act as a water removal device and importantly, tell you when there is a problem. How does it do that you ask? When its filters start to block more frequently, there is more contamination in the system and you need to investigate before it gets into your equipment.